To date, with the general popularization of the 3rd Generation (3G) wireless network, the network transmission speed increases, and more and more services based on the 3G network, including the cell phone TV, are developed. With the increased speed of 3G network, using wireless network to transmit the TV signal and using the terminal equipment such as a cell phone or a wireless data terminal to watch TV are more and more popularized services. CMMB (China Mobile Multimedia Broadcasting) is a typical one in this kind of services.
FIG. 1 is a structural block diagram of the system of the traditional wireless data terminal supporting the multimedia broadcasting, and the system comprises a PC and a wireless data terminal. Wherein, the PC comprises a program control module and a customized player module, and the program control module is used to search the channels and pilot the programs, while the customized player module is used to play the audio and video data stream so that the users can watch programs. The wireless data terminal comprises a multimedia broadcasting processing chip, a multimedia broadcasting data processing module, a program management module, an AT command analysis module, and a protocol stack and a USB (universal serial bus) transmission module. Wherein, after the multimedia broadcasting processing chip performs the down-conversion and decoding of the digital signal, the multimedia broadcasting data processing module which connects with the multimedia broadcasting processing chip via the interface 1 repackages the decoded digital signal into a format which can be used by the PC, and sends the signal to the USB transmission module via interface 2, and then the decoded digital signal is transmitted by the UBS transmission module to the PC, meanwhile, the AT command analysis module receives the PC's AT command from the USB transmission module via interface 5 and performs the corresponding processing, if the command relates to the multimedia broadcasting, the AT command analysis module calls the program management module which connects with it via interface 4 to search the channels or order programs etc. Moreover, the program management module connects with the multimedia broadcasting processing module via interface 3, and the protocol stack connects with the AT command analysis module via interface 6 and with the USB transmission module via interface 7 respectively.
As a standard COM device based on the USB interface, such as interface 8 and interface 9 in FIG. 1, the wireless data terminal communicates with the PC, wherein, interface 9 is a two-way interface which is used to transmit the AT commands (such as registering the network, selecting programs, and so on) from both the PC and the wireless data terminal sides; interface 8 is a one-way interface, the wireless data terminal uses it to transmit the program data to the PC, and the PC receives the data from the COM interface, and decodes and plays the data.
To sum up, the wireless data terminal supporting the multimedia broadcasting can implement the function of playing the multimedia broadcasting program by cooperating with the PC. However, this kind of multimedia broadcasting wireless data terminal can only play the programs by working with its cooperative PC, and it cannot share the programs with others.